Feathers are produced in large quantities by the poultry industry. These feathers provide an inexpensive source of raw material for a variety of potential uses. Among other things, there has been considerable interest in developing methods of degrading feathers so they can be used as an inexpensive source of amino acids and digestible protein in animal feed.
Processes for converting feather into animal feed which have been developed to date include both steam hydrolysis processes and combined steam hydrolysis and enzymatic processes. See, e.g., Papadopoulos, M.C., Animal Feed Science and Technology 16, 151 (1986); Papadopoulos, M. C. et al., Poultry Science 64, 1729 (1985); Alderibigde, A. O. and D. Church, J. Anim. Sci., 1198 (1983); Thomas and Beeson, J. Anim. Sci. 45, 819 (1977); Morris and Balloun, Poultry Sci. 52, 858 (1973); Moran et al., Poultry Sci. 46, 456 (1967); Davis et al., Processing of poultry by-products and their utilization in feeds. Part I. USDA Util. Res. Rep. no. 3, Washington, D.C. (1961). Disadvantages of these procedures, such as the degradation of heat sensitive amino acids by steam processes and the relatively low digestibility of the resulting products, have lead to continued interest in economical new feather degradation procedures which do not require a harsh steam treatment.
Accordingly, an object of the present invention is to provide a process for hydrolyzing keratinaceous material which does not depend upon steam hydrolysis.
An additional object is to provide a process for converting keratinaceous material into amino acids at high yields of the amino acids.
A further object of this invention is to provide a hydrolyzed feather product useful as a feed ingredient which is highly digestible and provides a good quality source of dietary protein and amino acids.
A still further object of the present invention is to provide an economical animal feed which employs a hydrolyzed feather product as a dietary amino acid source.
The foregoing and other objects and aspects of the present invention are explained in detail in the Summary, Detailed Description, and Examples sections below.